The LED display screen system as a new type of display technology is gradually accepted by the market owing to its advantages such as energy saving, environmental protection, higher brightness and so on, and thus it is widely used in urban media and city traffic applications.
The LED display screen system in the traffic application field is usually used to display messages such as names of road, road conditions and speed limits. However, any one LED of a LED display screen may go bad or dead, and when the number of bad/dead LEDs is too large or an area of the LED display screen has too many bad LEDs, the display of messages would be negatively influenced, and even to having the LED display screen displaying wrong messages. Therefore, how to make the LED display screen system in the traffic application field to detect LEDs fault/error in time is one of the problems emergently to be solved.
The fault detection in a LED display screen system of prior art is carried out by forming a circuit loop constituted by a receiving card, LED display unit boards and a monitoring board/card, more details can refer to the Chinese utility patent application submitted by the same applicant of the present invention on Jun. 25, 2012. The application number of the Chinese utility patent application is CN2012102110656.7, and the title of the Chinese utility patent application is “state detecting apparatus and detecting method of LED display screen”. The receiving card outputs data and control signals to the LED display unit boards. The LED display unit boards each include an input interface and an output interface, and transmit data signals to the next stage LED display unit board thereof. The output interface of the last stage LED display unit board is electrically connected to the monitoring board. The monitoring board/card receives the data outputted from the last stage LED display unit board and processes the received data, and then transmits/delivers the processed data to the receiving card. The receiving card analyzes received data and hereby obtains a LED fault condition of the LED display screen.
However, the prior art LED display screen system has the following disadvantages: (1) a LED box equipped with the LED display unit board(s) therein has excessive number of connection cables and thus is complicated; (2) the additional monitoring board is needed and thus the cost is higher. Accordingly, it is necessary to provide a LED fault detection solution with simplified connection and reduced cost.